Small Form-factor Pluggable (SFP) units represent one example of standardized hot-pluggable transceiving units. SFP units are standardized units adapted to be inserted within a chassis. A suite of specifications, produced by the SFF (Small Form Factor) Committee, describe the size of the SFP unit, so as to ensure that all SFP compliant units may be inserted smoothly within one same chassis, i.e. inside cages, ganged cages, superposed cages and belly-to-belly cages. Specifications for SFP units are available at the SFF Committee website.
SFP units may be used with various types of exterior connectors, such as coaxial connectors, optical connectors, RJ45 connectors and various other types of electrical connectors. In general, an SFP unit allows connection between an external apparatus, via a front connector of one of the aforementioned types, and internal components of a hosting unit, for example a motherboard, a card or a backplane leading to further components, via a back interface of the SFP unit. Specification no INF-8074i Rev 1.0, entitled “SFP (Small Form-factor Pluggable) Transceiver, dated May 12, 2001, generally describes sizes, mechanical interfaces, electrical interfaces and identification of SFP units.
The SFF Committee also produced specification no SFF-8431 Rev. 4.1, “Enhanced Small Form-factor Pluggable Module SFP+”, dated Jul. 6, 2010. This document, which reflects an evolution of the INF-8074i specification, defines, inter alia, high speed electrical interface specifications for 10 Gigabit per second SFP+ modules and hosts, and testing procedures. The term “SFP+” designates an evolution of SFP specifications.
INF-8074i and SFF-8431 do not generally address internal features and functions of SFP devices. In terms of internal features, they simply define identification information to describe SFP devices' capabilities, supported interfaces, manufacturer, and the like. As a result, conventional SFP devices merely provide connection means between external apparatuses and components of a hosting unit, the hosting unit in turn exchanging signals with external apparatuses via SFP devices.
Recently, SFP units with internal features and functions providing signal processing capabilities have appeared. For instance, some SFP units now include signal re-clocking, signal reshaping or reconditioning, signals combination or separation, signal monitoring, etc.
In the field of video transport, advances have been made recently for transporting the payload of a video signal into Internet Protocol (IP) packets (e.g. Serial Digital Interface (SDI) video payloads encapsulated into IP packets). Furthermore, an SFP unit can be adapted to receive the IP flows transporting the video payloads, and to process the video payloads.
One issue with the transport of video IP flows on an IP networking infrastructure is that video IP flows generally require a subsequent amount of bandwidth (which can lead to network congestion), and are very sensitive to delays. The currently deployed IP based video distribution infrastructures do not always make usage of the available bandwidth in an optimized manner. For example, an equipment receives a plurality of video IP flows simultaneously, but only uses one of the video IP flows at a time. In another example, an equipment (e.g. a multiviewer) receives a plurality of video IP flows transmitted at full resolution, and scales down the plurality of video IP flows to a lower resolution in order to display each one of the plurality of video IP flows in a monitoring window with a lower resolution.
US patent application 2014/0028907 A1 by Nuyttens et al. aims at optimizing the delivery of a video signal by using a progression mechanism to separate a video signal containing a video frame into multiple streams. The multiple streams each include data that, when combined by a decoder, form an image having a resolution that depends on a number of streams that are being combined and that is less than full-resolution when the number of streams that are being combined is less than the number of streams into which the video frame is divided. However, with this mechanism, the transmission of a large number of video signals leads to the transmission of an exponentially larger number of corresponding streams. Therefore, this mechanism is adapted for the transmission of a small number of video signals, but may not scale in the case of a video distribution infrastructure for transporting a large amount of video signals. Furthermore, on a large IP networking infrastructure, significant delays may occur between the streams, rendering the reconstruction of a particular image with a particular resolution ineffective because of the delays between the streams which compose the particular image.
Therefore, there is a need for a new standardized hot-pluggable transceiving unit providing bandwidth optimization capabilities.